This is where the harmonic balancer comes in. The circular device, made of rubber and metal, is bolted at the front end of the crankshaft to help absorb vibrations. It's usually connected to the crank pulley, which drives accessories like the air conditioner.
Additional costs: Ground water wells can also be tested for radon, then, if needed, can get a water radon mitigation system installed. Installing a water radon mitigation system runs from $1,000-$4,500, and maintenance runs $0 to $150 annually.
If you do need a system installed in your home, expect to pay between $750 and $3,000 for a professionally installed radon mitigation system. The size of your house, the type of system you have installed, and the level of radon gas in your house will determine where you fall on that cost spectrum.